迴圈用於重複執行一些程式塊。從上一講的選擇結構,我們已經看到了如何用縮排來表示程式塊的隸屬關係。迴圈也會用到類似的寫法。for迴圈for迴圈需要預先設定好迴圈的次數(n),然後執行隸屬於for的語句n次。基本構造是for 元素 in 序列: statement舉例來說,我們編輯一個叫forDemo.py的檔案for a in [3,4.4,'life']: print a 這個迴圈就是每次從表[3,4.4,'life']
1. 基本文法isinstance(object, classinfo)Return true if the object argument is an instance of the classinfo argument, or of a (direct, indirect or virtual) subclass thereof. Also return true if classinfo is a type object (new-style class) and object is
在python運行過程中出現如下錯誤:python錯誤:ImportError: No module named setuptools這句錯誤提示的表面意思是:沒有setuptools的模組,說明python缺少這個模組,那我們只要安裝這個模組即可解決此問題,下面我們來安裝一下:在命令列下:下載setuptools包shell# wget
Python內建函數(3)——any,python內建函數any英文文檔:any(iterable) Return True if any element of the iterable is true. If the iterable is empty, return False. Equivalent to:def any(iterable): for element in iterable: if element:
Python內建函數(4)——ascii,pythonascii英文文檔:ascii(object) As repr(), return a string containing a printable representation of an object, but escape the non-ASCII characters in the string returned by repr() using \x, \u or \U escapes. This
Python內建函數(5)——bin,python內建函數bin英文文檔:bin(x) Convert an integer number to a binary string. The result is a valid Python expression. If x is not a Python int object, it has to define an __index__() method that returns an integer.說明: